Machine tools



C. D. CQFFIN MACHINE TOOLS Aug. 17, 1965 12 Sheets-Sheet 1 Original Filed Jan. 26, 1960 INVENTOR.

CLAUDE D. CoFFlN ,4T TOR/VEYS Aug. 7, 1965 c. D. COFFIN 3,200,680

MACHINE TOOLS Original Filed Jan. 26, 1960 12 Sheets-Sheet 2 H I M CLAUDE l li i gifm V ATTORNEYS C. D. CQFFIN MACHINE TOOLS Aug. 17, 1965 12 Sheets-Sheet 3 Original Filed Jan. 26, 1960 Aug. 17, 1965 c. D. COFFIN 3,200,630

MACHINE TOOLS Original Filed Jan. 26, 1960 1.2 Sheets-Sheet 4 CUP CLUTCH 63 COF BRAKE INVENTOR. 0. Co FFIN CLAUDE BY I 76.7 'WWI ATTORNEYS c. D. COFFIN mum TOOLS Aug. 17, 1965 12 She ets-Sheet 5 Original Filed Jan. 26. 1960 ATTORNEYS 12 Sheets-Sheet 6 C. D. COFF IN MACHINE TOOLS Original Filed Jan. 26, 1960 Aug. 17, 1965 INVENTOR, CLAUDE D. COFFIN M, %%JZM,M%W.

ATTORNE vs CURTIS C05 LS COFLS C. D. COFFIN Aug; 17,1965

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MACHINE TOOLS Original Filed Jan. 26, 1960 3,3 Sheets-Sheet 11 E 3% a H l I 628m mlou a a W m m q. mm Q5 mm mm *m SN mm umutm mm i U) l H C. D. COFFIN MACHINE TOOLS Aug. 17, 1965 12 Sheets-Sheet 12 Original Filed Jan. 26, 1960 INVENTOR. CLAUDE D. Con-m Arm/Mays United States Patent Office Biddfihll Patented Aug. 17, 1965 3,206,680 MACHINE TGOLS Claude D. 'Cofiin, Cleveland, Ghio, assignor to The Warner & Swasey lCompany, Cleveland, Ohio, a corporation of ()hio Continuation of application Ser. No. 4,765, Jan. 26, 1960.

This application .luly 27, 1964, Ser. No. 386,435 14 Claims. (Cl. 82-2.5)

This invention relates to machine tools and particularly to a single spindle automatic bar machine for performing operations on bar stock.

This application is a continuation of my copending application Serial No. 4,765, filed January 26, 1960, now abandoned.

According to the present invention, a machine tool is provided which is automatically operable to perform a number of operations on a workpiece in a preselected sequence. Although the present invention has many and varied uses, it is of particular advantage when employed in connection with automatic bar machines for machining bar stock. The machine of the present invention is designed to automatically repeatedly machine bar stock, out off the machined piece and advance the bar to position it for a subsequent machining operation.

The present invention eliminates a number of hand operations previously required by an operator after the machine has finished its cycle and a particular bar has been machined and used up. in the present invention when a new bar has been loaded into the machine the operator actuates a single push button to initiate the substantially full automatic operation of the machine. This automatic operation includes the cutting off of a piece of the bar to square up the bar end, the machining cycle and the sequencing of the machine after the bar has been used wherein the remnant bar is e ected and parts of the machine are prepared for the loading of a new bar. When the bar has been depleted and a short length thereof remains, the machining operations are stopped automatically and certain parts of the machine are operated in the proper sequence so that the remaining short bar is auto,

matically ejected from the machine and the machine is prepared to permit the loading of a new bar.

During the machining cycle a number of operations are performed in a preselected sequence. These operations include movement of a tool holding carrier or turret in forward and reverse directions longitudinally of the bar, indexing of the turret to a new tool supporting face, forward and reverse movement of a cutoff device for cutting off a piece of the bar, opening and closing of a bar gripping chuck and forward and reverse movement of a bar feeding mechanism. In the present invention these operations are performed automatically in a preselected sequence during the machining of the bar and in a different sequence after the bar has been shortened to a predetermined length.

Heretofore no provision has been made for automatically sequencing a bar machine after the last piece has been completed on a particular bar. It was previously necessary for an operator to perform a number of tiresome and time consuming hand operations to set up the machine after the bar had been used to condition it for the reception of a new bar. Furthermore, after these manual operations were performed and the new bar had been loaded, the operator was required to perform additional hand operations so that a small piece was cut off from the new bar to square up the end of the bar prior to the initiation of the machining operations. As an example, an operator has heretofore been required to operate a number of push buttons after the last piece of a bar has been machined to open the chuck, effect forward movement of the bar feed mechanism to remove the short piece, close the chuck after the new bar has been loaded, effect retraction of the bar feed mechanism, start rotation of the spindle, start the cut off operation, open the chuck, effect movement of the bar feed mechanism forward to advance the bar against a stock stop, again close the chuck and reverse the bar feed mechanism. Only after these operations have been performed can the machining operation of the machine be initiated.

By means of the present invention the operator merely loads in a new bar and operates a single push button to initiate substantially fully automatic operation of the machine. The machine will automatically go through the steps required to cut off a small piece of the bar to square up the end and then will proceed to effect the machining of the first piece and continue the machining cycle until the bar has attained a predetermined short length. When this occurs the turret remains in its retracted position and the cut off operation is initiated. When cut off of the last piece is completed, the cut off slide retracts and the spindle stops. The chuck then opens and the bar feed mechanism pushes the short piece from the chuck and the machine stops with the various parts thereof in a condition to receive a new bar. The operator then loads the new bar and presses the push button as before.

The machine is also designed so that the cut off operation can be initiated during indexing of the tool turret to any one of its stations. In addition, the cut off operation can be progressing simultaneously with a machining operation on the bar.

A further important aspect of the invention is the provision of an automatic bar machine wherein the various operations are automatically performed in the proper sequence by electrical control means which control the operated parts of the machine. The electrical control means includes a number of limit switches which are actuated at preselected times automatically to control electrical circuits.

It is therefore an object of the invention to provide a machine tool which is substantially fully automatic in operation whereby a number of tiresome and time consuming hand operations now necessary in known machines are eliminated and workpieces may be rapidly and accurately machined at low cost.

It is a further object of the invention to provide a bar machine of improved construction wherein the machine is automatically sequenced after machining operations on a bar have been completed to prepare for the reception of a new bar.

It is another object of the invention to provide a bar machine for automatically repeatedly performing machining operations on bar stock in a preselected sequence and to automatically sequence the machine after the bar has been used to condition the machine for reception of a new bar.

It is a further object of the invention to provide a machine as defined in the preceding object wherein the automatic performance of the machine is initiated by actuation of a single control switch.

It is a still further object of the invention to provide a machine as defined in the next preceding object wherein the machining operations are automatically stopped in response to the bar attaining a predetermined short length.

it is a still further object of the invention to provide an automatic bar machine effective in response to the actuation of a single control switch to automatically cut off a small piece from a new bar and then to proceed with the automatic machining of the bar and after the bar is used to eject the remnant bar and prepare for the reception of a new bar.

It is still another object of the invention to provide an automatic bar machine for performing operations on bar I? stock wherein the bar is repeatedly machined and advanced subsequent to the cutting off of a piece of bar with improved means for permitting the cut-oif operation to be performed simultaneously during the machining operations on the bar.

It is a further object of the invention to provide a fully automatic bar machine including operated parts which are automatically operated in proper sequences by electrical control switches and circuits.

The invention will become apparent from the following description taken in conjunction with the accompanying drawings forming part of this specification, in which FIG. 1 is a view in top plan of a machine tool constructed in accordance with the teachings of the invention;

FIG. 2 is a view in front elevation of the machine shown in FIG. 1;

FIG. 3 is a fragmentary top plan view showing the bar feed mechanism and the chuck actuating assembly of the machine;

FIG. 4 is a fragmentary front elevational view of the parts illustrated in FIG. 3;

FIG. 5 is an enlarged fragmentary view with parts shown in section and parts shown in elevation illustrating the parts shown in FIGS. 3 and 4; 7

FIG. 6 is a diagrammatic representation of a fluid circuit for operating parts of the machine;

FIG. 7 is a view in section showing the transmission for effecting movement of the cut-off device at feed and rapid traverse speeds;

FIG. 8 is a view in side elevation showing the cut-off device for cutting off a piece of the bar;

FIG. 9 is a view in section taken along the line 9-9 of FIG. 8;

FIG. 10 is a view in section taken along the line 10-10 of FIG. 8;

FIG. 11 is a developed view in section showing parts of the cut-off device and the cam drum operated with the cut-off slide;

FIG. 12 is a view in elevation showing the cam drum illustrated in FIG. 11 and'the mounting thereof;

FIG. 13 is a diagrammatic representation of .the machine including transmissions and fluid circuits utilized therein;

FIGS. 14 through 17 are diagrammatic representations of electrical control circuits employed in the machine;

FIG. 18 is an elevational view showing a portion of the bar feed mechanism is retracted position and a limit switch associated therewith; and

FIG. 19 is a view in elevation of the machine showing relative locations of various limit switches and cams employed in the machine.

Although the invention will be described as employed in connection with a machine for operating on bar stock, it 'is understood that the principles of the invention may also be employed in connection with other types of machines for operating on work pieces of various configurations. Referring initially to FIGS. 1 through 4, the main elements of the machine tool may now be described. The machine tool is supported on a surface 1 and includes a pan 2 and vertically extending frame and housing portions including the bed 3 and the headstock 4. The headstock rotatably supports a hollow spindle 5 which is provided at its outer end with a conventional collet chuck .6 (FIG. 5) as is well understood in the art. The collet chuck is arranged to open and close in order to respectively release and grip the bar stock. A control panel P is located at the front of the machine and includes a number of manually actuatable switches for controlling operation of parts of the machine.

In order to actuate the collet chuck there is provided in a conventional manner a chuck actuating mechanism '7 (FIG. 5) which will be described hereinafter in greater detail. The machine .tool alsoincludes a bar feeding mechanism 8 which is designed to move longitudinally of the spindle axis to advance the bar stock subsequent to the operation of the cutoff mechanism for cutting off a piece of the bar stock. The bar feed mechanism operates to advance the bar stock andthen retracts to its rear position relative to the advanced bar stock. As will appear hereinafter, the bar feed mechanism operates automatically to advance the bar stock subsequent to opening of the collet chuck to'a bar releasing position.

The machine also includes a tool carrier 9 in the form of a conventional turret which may have five'or a different number of faces each including means to support suitable tools. The carrier 9 is part of an elongated support member extending through theheadstock '4 and having at its left-hand end, as viewed in FIG. 1, a control drum 10 including means for adjustable mounting a number of switch actuating dogs for effecting various controlling functions, as will appear hereinafter. The turret 9 and the drum 10 are arranged for movement longitudinally of the spindle axis as a unit. The turret 9 is movable relative to the bar stock at feed and rapid forward and reverse traverse speeds so that the tools carried thereby may be quicky brought into and out of machining position and may be moved at a feed speed to effect the machining operation as will be understood. The turret and the drum 10 are also arranged for indexing rotation as a unit about an axis parallel to the spindle axis so that different faces and tools carried by the turret may be indexed into proper relationship to the bar stock. The support for-the turret 9 is mounted for longitudinal movement by means of front and rear parallel extending ways 11 and 12.

In order to permit additional machining operations upon the bar stock there is provided a pair of conventional front and rear cross slides 13 and 14 mounted for'movement transversely of the sprindle axis. As will presently appear, these cross slides are movable at rapid traverse and feed -speeds as will be well understood.

In order to cut off a piece of the barwhich'has been machined, there is provided a separate cutoff mechanism 15 (FIG. 8) which is mounted for movement at rapid traverse and feedspeeds transversely of the spindle axis.

There is provided a support tube 16 for supporting the bar stock when the stock is loaded into the machine. The tube 16 at its'left-hand end as viewed in FIG. 1 is secured to a pivot head 17 which is mounted by a support 18 for pivotal movement about a vertical axis as viewed in FIG. 2. A clamp device 19 is provided at the righthand end of the tube, as viewed in FIG. 1, for clamping the tube in its operative bar supporting position. The clamp 19 is carried by a suitable support 20and mounts an arm 21 which extends toward the observer, as viewed in FIG. 2. The arm 21 is designed to support the tube 16 when the tube is pivoted with pivot head 17 about its vertical axis.

The spindle 5, at its right-hand end as viewed in FIG. 5, has an annular flange 23 secured thereto which has an extending nose 24 with a frusto-conical opening in which is received resilient jaws 26 of the collet chuck. As is conventional in the art, resilient pads 27 may be secured to the jaws 26 to grip the bar stock. In order to open and close the collet chuck, there is provided a plurality of pivoted fingers 28 (only one of which is shown) which arepivoted to a housing 29 secured as by threading a sleeve 30, whichis slidable freely within the spindle 5. The sleeve Si) is secured as by threading to a thin wall section 31a of an extension from the resilient jaws 26.

The .fingers .28 include short projections 28 which engage a reaction ring 28" forming part of the spindle. The fingers 28 carry rollers which cooperate with an inner tapered surface of a hollow cone 33 which is slidable on the outer surface of the housing 29. The cone 33 includes an annular groove 34 in which may be posiends to a bracket 36 supported by the ways 11 and 12.

When the lever is pivoted it effects sliding movement of the cone 33 relative to the housing 29 and relative to the fingers 28 so that the fingers 28 are pivoted and the sleeve 39 is moved to the right or left, depending upon the direction of pivotal movement of the lever. As a result, the collet chuck can be opened or closed by actuation of the lever 35. If the lever 35 is pivoted in a clockwise direction as viewed in FIG. 5, then the cone 33 is moved to the right and the finger 28 is pivoted in a clockwise direction by the resiliency of the jaws 26 so that the sleeve is moved to the right which opens the collet. Pivoting the lever 35 in a counterclockwise direction operates to close the collet.

Operation of the collet chuck is effective to actuate a limit switch CLS (FIG. 4) which is conveniently carried by the bracket 36. The switch CLS is in the path of movement of the lever 35 and is actuated by the lever when the lever is pivoted. As will appear hereinafter, the switch CLS controls a number of electricalcircuits.

As best shown in FIG. 5, the bar feed mechanism includes an axially movable, nonrotatable head assembly 37 supported on the ways 11 and 12 and which surrounds an inner hollow sleeve 38 which has secured thereto as by welding a feed finger tube 39 extending slidably within the collet actuating sleeve 30. The tube 33 carries at its right-hand end, as viewed in FIG. 5, a plurality of resilient fingers 40 which are arranged to grip the bar stock during advancement of the bar feed mechanism to move the bar forward through the then open collet chuck, and to move relative to the bar stock when the bar feed mechanism is retracted subsequent to closing of the col let chuck. The fingers 49 are designed to be in continuous engagement with a bar except when the bar attains a predetermined short length. The sleeve 38 may have secured thereto a filler tube 41 which then extends through the finger tube 39 to accommodate bars of small cross-sectional area. When such small bars are used, the fingers 40 are modified to permit gripping of the smaller bars but when smaller bars are not used, the filler or adapter tube 41 is removed.

The sleeve 38 and the tube 39 are supported to rotate with the spindle relative to the head assembly 37 by means of suitable bearings'42 between the head assembly 37 and the sleeve 38.

As shown in FIGS. 5 and 18, the head 37 includes an annular part 42 having depending portions 43 on each side thereof to which are secured hollow members 44 through which extend the ways 11 and 12. A ring 45 is attached to the right-hand face of the part 42 to surround the finger tube 39. A ring-shaped member 46 is positioned within the part 42' and is biased to the left in the absence of a bar to engage a shoulder of the part 42' by means of a plurality of springs 47 (FIG. 5) located within recesses of the member 46 and engaging the inner surface of the ring 45. When in engagement with the shoulder of part 42, the member 46 is spaced longitudinally of the ring 45 to provide a gap therebetween. The feed finger tube 39 is rotatably supported within the member 46 by a bearing 42 having an outer race 49 and an inner race 50. An externally threaded member 48 threads into the member 46 and engages the outer bearing race 49 to hold it against a shoulder of the member 46. The inner race 50 is secured in position by means of a lock nut 51 threaded on the sleeve and engaging with a washer 52.

The finger tube 39 and sleeve 38 with nut 51 secured thereto rotate within the bearing 42 and the latters associated parts when the work spindle and the bar stock in the finger tube 39 and gripped by the collet chuck 6 are rotating as will be well understood.

FIG. 18 illustrates the relationship of the parts of the bar feed mechanism 8 when the latter is in its most re= tracted position and bar stock is in the finger tube 39 and is being gripped by the fingers 4t). A switch actuating rod 53 is carried by the bar feed mechanism 8 and is slidable relative thereto by being slidably mounted in spaced bearing bores formed therein. The rod 53 at its righthand end, as viewed in FIG. 18, is provided with a member 56 adjustable thereon and having an annular groove in which is positioned the free end of a pin 57 extending into an opening of the member 46 through an elongated slot 58 in the wall of the annular part 4-2 of the head 3'7 of the bar feeding mechanism. The pin 57 is fixed to the member 46 by a suitable setscrew.

The opposite or left-hand end of the rod 53, as viewed n FIG. 18, adjustably mounts a nut 55. A limit switch EFLS (empty finger limit switch) is secured to the fixed support 20 of the machine. The nut 55 on the rod 53 is adjusted so that it will just be in non-actuating engagement with the actuating member 54 of the switch EFLS when the bar feed mechanism 8 is in its most retracted position prior to its forward feeding movement and the fingers 43 of the finger tube 39 are gripping bar stock. This is the condition illustrated in FIG. 18 and it will be noted that the ring 45 of the head of the bar feed mechanism is contacting the right hand end of the member 46 and the springs 47 therebetween are compressed.

Assuming the initiation of the forward or feeding movement of the bar feed mechanism 8 while bar stock is be ing gripped by the fingers 49, the member 46, sleeve 38 and finger tube 39 momentarily are stationary due to the frictional grip of the fingers 46 on the bar stock.

This condition obtains until the inner side of the annular flange at the left side of the part 42 of the head 3'7 of the bar feed mechanism engages the left hand end of the member 46, after which the member 46, sleeve 38 and finger tube 39 move unitarily with the part 42 to effect feeding movement of the bar. movement of the referred to elements takes place there is a gap between the ring 45 and the right hand end of the member 46 and the springs 47 are expanded.

During the initial and momentary position of the forward or feeding movement of the bar feed mechanism relative to the then stationary member 46, sleeve 38 and tube 39 thereof, the rod 53 is held stationary by the pin 57 carried by the member 46 and the bar feed mechanism moves slidably toward the right relative to said rod. When the member as, sleeve 38 and finger tube 39 thereafter move unitarily with the part 42 of the bar feed mechanism to feed the bar stock the rod 53 moves as a unit therewith toward the right and without any relative movement between it and the bar feed mecha l'liSIIl.

Now assuming that the bar feed mechanism has fully advanced in the bar feeding direction, the parts are in the relationship shown in PEG. 5. When this condition obtains the movement of the bar feed mechanism at the proper time in the cycle is automatically reversed by means hereinafter explained and said mechanism starts to move from its advanced right hand bar feed position toward its fully retracted left hand position. The initial part of this retracting movement causes the part 42 of the bar feeding mechanism and ring 45 secured thereto to move relative to the member as, sleeve 38 and finger tube 39 until the ring 45 compresses the spring 47 and engages the right hand end of the member 46, after which said member 46, sleeve 38 and finger tube 33 will move as a unit with the part 42' of the bar feed mechanism and with the ring 45 in engagement with the member 46 as indicated in FIG. 18 with the gap between said ring and member being closed.

The relative movement last referred to occurs because the frictional engagement of the fingers 40 with the bar stock restrains the member 46, sleeve 38 and When this unitary finger tube 39 against retracting movement until said elements are positively moved by the ring 45 engaging therewith and moving as a unit with the part 42 to which the ring is secured. When all of the parts of the bar feed mechanism move rearwardly as a unit then the fingers 40 frictionally slide along the bar stock until the bar feed mechansim is in its most retracted position,-

i.e., the position of FIG. 18.

When the bar feed mechanism commences its rearward movement after completing its forward movement, the nut 55 on the rod 53 is spaced from the actuator 54 of the switch EFLS and hence the rod 53 is functionally idling during the rearward movement of the bar feed mechanism. and at the end thereof the nut 55 is just contacting the switch actuator 54 as previously explained and as shown in FIG. 18.

When the bar feed mechanism reaches its most rearward position and bar stock is in the fingers 40 it will automatically be caused to move in the forward or bar feeding direction as soon as a workpiece has been machined and cut off by mechanism hereinafter described. The described functioning of the bar feeding mechanism hereinbefore set forth is the normal functioning thereof when bar stock is in the fingers 40.

Now assuming that the bar feed mechanism is in its most forward bar feed position and starts its rearward movement when the bar stock has been substantially used up in the production of workpieces so that only a remnant of the stock is present in the collet chuck. Under such conditions as soon as the fingers 49 leave the remnant of bar stock so there is no frictional resistance offered to the movement of the fingers 49 along the bar stock then the springs 47 are of sufiicient strength to expand and to move the member 46 away from the ring 15 to provide a gap therebetween and until the member 46 engages the annular flange at the left hand side of the part 42 of the bar feed mechanism. When this condition obtains and the bar feed mechanism reaches its most retracted or left hand position the member 46 is in a left hand position further than its normal left hand position when the bar feed mechanism is fully retracted, that is, the member 46 is farther to the left by the distance of the gap between the ring 45 and the right hand end of the member 46. Consequently this additional left hand movement of the member 46 acts through the pin 57 to move the rod 53 toward the left relative to the bar feed mechanism so that the nut 55 which normally just contacts the switch actuator 54 now functions to move said switch actuator 54 and operate the limit switch EFLS. This operation of the limit switch EFLS closes the normally open contact 290 thereof, see FIG. 17. V

The actuation of switch EFLS as just described occurs prior to the completion of the machining of the last workpiece in the collet chuck of the machine. The control circuit, as later explained, is such that the machine completes its operative cycle and the machining of the last workpiece and then, due to the operation of switch EFLS, stops its sequential operations although the work spindle continues to rotate. That is, the cutoff slide, the

cross slides and turret slide then will be in retracted postion and the turret will be indexed to position the stock stop to be engaged by the end of the new bar stock when the latter is loaded into the machine. The cutoff, tool then will have cut off the last workpiece, the collet chuck will be open and the bar feed mechanism will have moved to its most forward feed position. The operator now loads a new length of bar stock into the bar feed mechanism until the end thereof projects through and beyond the collet chuck to a position where it can be squared off by the cutoff tool. The operatornow presses the cycle start button whereupon the collet chuck closes, the cutoff slide moves forwardly and the cutoff tool squares the end of the new bar stock and the cutoff slide retracts, the bar feed mechanism retracts, the

, chine continues automatically to function to perform the sequential operations of the work cycle. The control means for effecting the operations referred to are ex plained in detail hereinafter.

It will be understood that the machine continues automatically to machine workpieces from the new length of bar stock until the feed fingers 40 leave the remnant of the bar stock and the EFLS switch is again actuated as explained above.

When the bar feed mechanism is moved to its fully forward position to advance the bar, it actuates a limit switch designated 'as bar feed forward limit switch BFFLS (FIG. 3) which may be a conventional micro- 'switch. This switch is shown as mounted by the bracket 36 and has an actuating member 59 which is engageable by the head 37 to operate the switch for effecting controlling functions described hereinafter.

An additional switch designated asbar feed back limit switch BFBLS (FIG. 3) is actuated when the bar feed mechanism is. fully retracted to initiate certain control functions. This switch is a conventionalmicroswitch and is carried by the support 20 so that its actuating member is engaged by a part of the bar feed mechanism when such mechanism is fully retracted.

The details of construction of the cut-off mechanism 15 may now be described. Asshown in FIG. 8, the cutoff mechanism includes a cut-off blade 66 having a sharp edge 60a which is arranged to cut off a piece of the bar. The blade 60 is secured to a toolholder 61 which is in turn attached to a slide 62. The slide is adapted to reciprocate along an axis ext-ending transversely of the spindle axis so that the blade 60 may be advanced and withdrawn with respect to the .bar. For this purpose the slide 62 is slidably mounted by means of a support 63 which may be attached to a portion 63' of the machine.

In order to effect movement of the slide 62 a cam follower wheel 64 is rotatably supported by a bracket 65 which is secured to the upper portion of the slide as viewed in FIG. 10. The wheel 64 is positioned within a spiral groove 66 formed in a cam disk 67 which is keyed to a shaft 68 mounted for rotation by the support 63 and the portion 63'. When the cam disk 67' is rotated the groove 66 will move with respect to the wheel 64 and due to the variable radius of the groove the slide 62 will be displaced to the right or left, as viewed in FIG. 10, depending upon the direction of rotation of the cam disk 67. It is noted that the support 63 includes a horizontally extending slot 70 to accommodate the upwardly extending neck of the bracket 65 during movement of the slide 62.

The cam disk 67 is formed on its periphery with gear teeth 71 which mesh with a gear 72, shown in FIG. 8, which when rotated will effect rotation of the cam disk 67. 'As shown in FIG. 9, the gear 72 is keyed to a shaft 73 which is driven from the spindle 5 through a transmission describcd hereinafter. The shaft 73 in FlG. 9 is a continuation of the shaft 73 shown in FIG. 11, which in turn is operatively connected to a shaft 74, shown in FIG. 7. As will presently. appear the slide 62 is moved at rapid traverse and feed speeds which are proportional to the speed of rotation of the spindle.-

The transmission for driving the cutoff slide 62 at feed and rapid traverse rates correlated to the rotation of the spindle 5 is illustrated in FIG. 7 and includes a shaft journ'aled for rotation in spaced portions of the transmission housing. An electrically operated cutoff feed brake GOP is mounted on the shaft 74 and acts when energized to prevent rotation of said shaft. As previously stated, the shaft 74 is operatively connected to the shaft 73 which drives the cam disk 67 that actuates the cutoff slide 62.

The sleeve 75 is freely rotatable on the shaft 74 and has fixed thereto a gear 75. The sleeve 75 is operatively connected to one element 74' of a magnetic clutch designated as the cutoff rapid traverse clutch CORT and which element is freely rotatable on the shaft 74 with the sleeve 75' and gear 75. The element 74 of the magnetic clutch CORT is splined to the shaft 74, wherefore when the clutch is engaged, rotation of gear 75 and sleeve 75 acts through clutch element 74 to rotate clutch element 74" and, in turn, the shaft 74. The shaft 74 beyond the CORT clutch has fixed thereto a gear 86.

The transmission housing also rotatably mounts a shaft 77 parallel to the shaft 74. A two-gear cluster is freely rotatable on the shaft 77 and consists of a smaller gear 76 which constantly meshes with the gear 75 and a larger gear 3'7. The gear 87 of the two-gear cluster constantly meshes with a gear 37 fixed on shaft 88 rotatably carried by the transmission housing in parallel relationship to the shafts 77 and 74. The shaft 88 extends outwardly of the transmission housing and has fixed thereto a gear 89 which constantly meshes with a gear 967 fixed to the spindle 5.

It will be seen that when the spindle 5 is rotating the two-gear cluster will freely rotate on the shaft 77 and the gear 75 and sleeve 75 will freely rotate on the shaft 74, provided the CORT clutch is disengaged.

The larger gear 57 of the two-gear cluster has secured thereto in parallel relationship to the axis of the gear but spaced radially therefrom a stub shaft on which a wide gear 78 is free to rotate. The gear 78 constantly meshes with a gear 79 formed on a sleeve as that is freely rotatable on the shaft 77. Also the gear 78 meshes with a gear 81 fixed to a portion 32 of the transmission housing and within which gear 81 the sleeve as is free to rotate. The gear 79 may be of the same pitch as, but will have a greater number of teeth than the fixed gear 81, as for example the gear "7% may have one more tooth than does the gear 01.

In FIG. 7, the gear 87 is shown as mounting an independently rotatable gear similar to the gear 78 and located intermediate the shafts 3t and 77. It will be noted that the gear 78 is of larger diameter than the other gear carried by the gear 87. If it is desired to change the gear ratio the gears 79 and 81 on the shaft 77 may be replaced with larger gears which would mesh with the other gear referred to carried by the gear 87 and at such time the gear identified by the numeral 78 would be removed from the gear 87.

It will be seen that when the gear 75 is rotatably driven through the gears E57, 39 and 99 by the spindle 5 and is rotating freely on the shaft 77, the gear 78 will roll around the fixed gear Si which functions as a circular rack and such rolling of the gear 78 will impart rotation thereto on its own axis in addition to its I circular orbital movement about the shaft 77, due to the rotation of the gear 87 of the two-gear cluster. The independent rotation of the gear 78 about its own axis, due to its rolling engagement with the fixed gear 81 and the greater number of teeth in the gear 79 than in the gear $1 imparts an increment of rotative movement to the gear 79 relative to the gear 81. Hence the sleeve 8t) that carries gear 79 rotates on shaft 7'7.

The sleeve 89 has splined thereto the shiftable element $3 of a magnetic clutch which is identified as the cutoff feed clutch COP. The other and fixed element of the magnetic clutch COP is keyed to the shaft 77 and hence when said clutch is engaged the rotation of gear 79, sleeve 89, clutch element 53, acts through the clutch element 84 to ro-tatably drive the shaft 77. The shaft 77 beyond the CO clutch has fixed thereto a pick-off gear 85 which constantly meshes with the pick-off gear 86 fixed to the shaft 74.

As previously stated, the shaft 74 may be driven at rapid traverse or feed speeds in timed relation to the rotation of the spindle 5 and such drive of the shaft 74 imparts rapid traverse or feed movements to the cutofi slide.

Assuming that the COF clutch is disengaged and the CORT clutch is engaged, the shaft 74 is driven for rapid traverse of the cutoff slide from the spindle 5 through gears 9d, 89, shaft 8%, gear 87, gear 76 of the two-gear cluster on shaft 77, gear 75, sleeve and the now engaged clutch elements 74' and 74" of the CORT clutch. At such time, the COP clutch will be disengaged and the rotation of the two-gear cluster on the shaft 77 and the rotation of the gear 78 on its own axis as it rolls around the fixed gear 81 merely imparts an idle rotation to gear 79, sleeve and element 83 of the COP clutch. Inasmuch as the shaft 74 is rotating and has fixed thereto the gear 86 which meshes with the gear fixed to the shaft 77, the latter will rotate idly within the rotating two-gear cluster, the sleeve 80 of the gear 79 and clutch element 33, while the element 84- of the COP clutch will rotate idly with the shaft 77 and relative to element 83.

Now assuming that the CORT clutch is disengaged and the COP clutch is engaged to impart feeding movement to the cutoff slide, the transmission illustrated in FIG. 7 operates as follows: The rotation of the two-gear cluster on the shaft 77 causes the gear 78 to roll around the fixed gear 31 to give the gear 78 independent rotation on its own axis and such independent rotation drives the gear 79 and sleeve fit} and element 83 of the COF clutch due to the greater number of teeth in gear 79 than in gear 81, which at this time is engaged with the element :74 thereof so that the shaft '77 is rotated on its axis within the two-gear cluster and sleeve 8%. This rotation of the shaft 77 acts through the pick-off gears 85, 5 to drive the shaft '74 at a rate to produce feeding movement of the cutoff slide.

When the shaft 74 is thus rotating for cutoff slide feed the gear 75 driven by the gear 76 and the sleeve 75 and element 7d of the now disengaged CORT clutch have independent and idle rotation on the shaft 74 while element 74 rotates with shaft 74 and relative to element 74-.

The engagement and disengagement of the COP brake, the CORT clutch and the COP clutch are effected automatically during the sequence of the operative cycle by control means hereinafter explained in detail.

The transmission housing includes a closure 91 which may be opened from its illustrated closed position to expose the transmission mechanism. The closure 91 is effective to control operation of a switch designated as switch CGDLS. This switch is operated when the closure is in its illustrated closed position and includes contacts in the electrical control circuits, as described hereinafter.

Referring now to FIGS. 11 and 12, there is illustrated a control arrangement which is operative during movement of the slide 62 to effect certain controlling functions. This control arrangement includes a cam drum 92 which is secured to a shaft @3 journaled by a portion of the machine structure. The drum 92 is rotated by means of a gearing arrangement including a gear 94 carried by the drum 92 in meshing engagement with a gear 5 fixed to the shaft 74 which, as previously described, is rotated at a speed proportional to the spindle speed. With this arrangement the drum 92 will rotate at a speed which is proportional to the speed of movement of the slide 62.

The drum 92 mounts a plurality of cam disks which cooperate with a plurality of switches to effect controlling functions during movement of the slide 62. In the illustrated embodiment the drum 92 mount-s three cam disks 96, 97 and 98 which have peripheral camming surfaces of preselected configuration for engaging in predetermined sequence actuating elements 99, 100, 101 of limit switches designated respectively as the cut off rapid traverse limit switch CORTLS, the cut off slide limit switch COSLS, and the cut off feed limit switch COFLS.

The purpose of these switches will be described hereinafter.

Referring now to FIG. 13, there is diagrammatically illustrated portions of the machine tool including transmissions and fluid circuits for operating the transmissions to control movement of the spindle, turret and the front and rear cross-slides. The power for driving the various parts is supplied by a suitable electrical motor 192 having a motor shaft 103 which drives the spindle through a transmission 104 which may be of conventional design similar to the transmission disclosed in PEG. 5 of Patent No. 2,644,222. Briefly, the transmission 104 includes a pair of gears 105 and 1116 loosely carried by the shaft 103 to be selectively fixed to the shaft by means of a pair of fluid operated clutches 8C2 and 8C3. The shaft in? also has fixed thereto a gear 167. The gears carried by the shaft 103 mesh with gears carried by a shaft 108, which in turn mesh with gears carried by a shaft 16?. A shaft 111} carries a suitable shiftable gear arrangement 111 which is arranged to selectively drivingly engage gears 112 and 113 fixed to the spindle 5 to obtain either a high or low speed range. The shaft 168 carries a clutch SC1 and the shaft 189 mounts a pair of clutches 8C4 and SCS. The transmission 1114 is designed to effect rotation of the spindle 5 at ten 'diiferent speeds, including five speeds within a low speed range and five speeds within a high speed range.

The various clutches in the transmission 104 are of the fluid operated type and are arranged to be operated under the control of a plurality of electrically energizablc solenoids SVA, SVB and SVC having respectively armatures 114, 115 and 116 which are connected to shiftable bodies 117, 118 and 119 of a plurality of valves. When the solenoids are energized and deenergized the valve bodies will shift to control the application of a pressure fluid from a pump to the clutches SC1 through SCS. As will presently appear, the solenoids are selectively energizable under the control of limit switches to establish the desired spindle speed. i

The front and rear cross-slides are of conventional construction and are arranged to be driven at feed and rapid traverse speeds to perform tooling operations upon the bar stock. As is conventional, the front and rear cross-slides are adapted for movementat feed speeds which are proportional to the speed of rotation of the spindle. For this purpose the cross-slides are drivingly connected to the spindle by means of a transmission 120'and a cam 12% which may be of conventional construction. This transmission includes a plurality of fluid operated clutches FC1 through PCS, which are operated by a plurality of electrically energizable solenoids FVA, FVB and PVC. These solenoids have armatures 12 1, 122 and 123 connected to shiftable bodies 12 125 and 126 of a plurality of valves which are shiftable to control the application of pressure fluid to the clutches FCI through FCS. The arrangement is such that any one of three feed speeds may be selected for the cross-slides.

The cross-slides may also be moved at rapid traverse speeds so that they may be rapidly advanced and retracted with respect to the bar stock. For this purpose a reversible rapid traverse motor 127 is provided which may be operatively connected to a part of the transmission 120 to move the cross-slides in opposite directions at the rapid traverse speed.

As stated hereinbefore, the machine tool includes a pentagon turret 9 having five faces with means for supporting tools thereon. The turret 9 is mounted for movement longitudinally of the spindle axis at feed and rapid traverse speeds and is additionally mounted for indexing rotation about the longitudinal axis to index the tool supporting faces into tooling relationship relative to the bar stock. The turret is moved longitudinally of the spindle axis by means of a turret feed cam 128 which has a spiral groove 129 therein, as described in the aforementioned patent. The cam 123 may be rotated in opi2 positedirections from the motor 127 through a transmission 131) to effect rapid traverse movements. of the turret in opposite directions. The motor 127 is controlled by motor starters RTF (FIG. 15) and RTR (FIG. 16) as will appear hereinafter.

The cam 128 can also be driven in one direction at a feed rate from the transmission 121) to effect the feed movement of the turret. When this is done the shaft of motor 127 rotates idly. The turret is operatively connected to the earn 128 by a cam follower131 having a portion within the groove 129.

As stated hereinbefore, a control drum 10 is carried by the turret support so as to be longitudinally movable and rotatably indexible with the turret. This control drum also includes five faces corresponding to the turret faces which have a plurality of longitudinally extending slots for adjustably mounting a number of dogs 10:: (FIG. 19) positioned to actuate a plurality of feed, limit switches which may be designated as FLSI through ELSA (PEG. l3), and a number of speed limit switches SLSl through SLS4 (FIG. 13). These feed and speed limit switches have actuating elements PS and are mounted in a suitable switch box A (FIG. l9).with the actuating elements adjacent to the path of longitudinal movement of the turret so as to be actuated by the dogs 19a on the control drum 10 during longitudinal movement of the turret at a rapid traverse speed. 7

As will appear hereinafter, a selected one of the speed limit switches SLS1 through SL841 is operated during movement of the turret in a forward direction at a rapid traverse speed to effect energization of a selected one of the solenoids SVA, SVB and SV C. Operation of the selected one of the speed limit switches results in rotation of the spindle at a predetermined speed. A selected feed limit switch is alsooperated during rapid traverse movement of the turret in the forward direction to effect energization of a selected one of the solenoids FVA, FVB and PVC to provide a selected-feed speed of the turret and also a selected feed speed of the front and rear crossslides.

lnorder to provide further control of the controlling electrical circuits there is provided an auxiliary cam drum 132 which is arranged for. rotation at a speed proportional to the speed of rotation of the turret feed cam 12%. The drum 132 includes means for adjustably mounting a number of dogs 132' adapted to actuate a plurality of limit switches designated as CDLS1 through CDLSW. These limit switches may be mounted in a suitable switch box B (FIG. 19) and have actuating elements CD adjacent to the cam drum 132 to be operated at preselected times during longitudinal movement of the turret.

In order to effect indexing rotation of the turret there is provided an index motor 133 which may be drivingly connected to the turret by means of suitable gearing 134 connected between the shaft135 of the motor 133 and the support for the turret. As will appear hereinafter, the energization of motor 133 is controlled by operation of the limit switch CDLSd associated with the cam drum 131- The turret support also carries an index control drum 136 which has provision for adjustably mounting a number of dogs 136 for operating actuating elements IL of a plurality of limit switches designated as index limit switches ILS-1 through 1LS13 (FIG. 13). These limit switches are arranged to be actuated at preselected times during the indexing operation of the turret. 'The switches 1LS1 through 1LS13 may be housed in a suitable switch box C located adjacent to the control drum 136 so that the switches may be actuated as the drum 136 rotates with the turret These limit switches are effective when actuated to control the controlling electrical circuits during the automatic operation of the machine. A Geneva limit switch GLS (FIG. 13) is also operated during indexing of the turret prior to the time when the turret is fully indexed.

As mentioned hereinbefore, the collet and bar feed mechanisms are pressure fluid actuated. The collet mechanism is actuated in responsetodisplacemcnt of a piston 150 positioned within a hollow cylinder 151 and having a piston rod 152 extending outwardly of the cylinder and operatively connected to a plunger 153, which in turn is connected to the lever 35. Displacement of the piston 150 within the cylinder 151 is controlled by a valve 154 including a shiftable valve body connected to an armature 155 associated with the collet solenoid 156 shown in FIG. 17 and referred to more fully hereinafter.

In FIG. 6 the body of the valve 154 is in its normal position when the solenoid 156 is de-energized. For this position of the valve body the collet chuck is closed inasmuch as a conduit 157 which leads to a source of pressure fluid is connected through a passage 153 of the valve 154 to a conduit 159 leading to the upper end of the cylinder 151 so that the piston 15% is forced downwardly to extend the piston rod outwardly of the cylinder and displace the plunger 153 toward the right as viewed in FIG. 5. The conduit 157 is connected to a conduit 1619 through a relief valve 161 with the conduit 1611 leading to a source of pressure fiuid such as a pump through a conduit 162. The portion of the cylinder 151 beneath the piston 156 is connected to drain through a conduit 163 which is connected to drain conduits 164 and 165 through a passage 166 of the valve 154. A spring member 167 may be connected to the shiftable valve body of the valve 154 to bias the valve body to its normal position when the solenoid 156 is de-energized.

When the collet solenoid 156 is energized the armature 155 and the valve body connected thereto is moved upwardly so that the conduit 159 is connected to the conduit 164 through a passage 158' of the valve 154, and the conduit 163 is connected to the conduit 157 through a passage 166 of the valve 154. As a result, the piston 151) is displaced upwardly as viewed in FIG. 6 to effect movement of the plunger 153 toward the left as viewed in FIG. for opening the collet chuck.

The bar feed mechanism is operated in response to displacement of a piston 163 within a hollow cylinder 169 and having a piston rod 17% extending outwardly of the cylinder 169. The piston rod 171) is operatively connected to the annular part 4-2 of the head assembly 37 so that movements of the piston rod will result in corresponding movement of the part 42'. 1 The piston 168 is displaced under the control of a valve 172 having a shiftable body connected to an armature 173 associated with the bar feed solenoid 174 shown in FIG. 17 and referred to more fully hereinafter. When the solenoid 174 is de-energized the pressure conduit 162 is connected to a conduit 175 leading to the upper end of the cylinder 169 through a passage 176 of the valve 172. The lower section of the cylinder 169 is connected to a conduit 177 which in turn is connected to the drain conduit 165 through a passage 178 of the valve 172. A spring 179 biases the shiftable body of the valve 172 into its normal position when the solenoid 174 is de-energized.

When the valve body is in its normal position pressure fluid is introduced to the cylinder 16% through the conduits 162 and 1'75 through the passage 176 so that the piston 158 is forced downwardly to effect displacement of a rod 171 to which the part 42' and the rod 170 are connected toward the left as viewed in FIG. 5 to displace the bar feed mechanism to its retracted position. When the solenoid 174 is energized, the armature 173 and the valve body attached thereto are moved upwardly as viewed in FIG. 6 whereby the conduit 175 is connected to the drain conduit 165 through a passage 1'76 of the valve 172, and the conduit 177 is connected to the conduit 162 through a passage 178' of the valve 172. As a result, the piston 16% is forced upwardly to elfect displacement of the rod 171 and the part 42' toward the right as viewed in FIG. 5 to advance the bar feed mechanism.

When the part 42' is moved to the right, its shoulder engages the member 46 whereby the tube 39 and the gripped bar also move to the right to effect feeding of the bar. During this time the ring 45 is spaced from the member 46. When the part 42' is retracted, while bar stock is gripped by the feed fingers 4t and the collet chuck, the ring 45 engages the member 16 and thereby retracts the tube 39 relative to the advanced bar. 7

In order to limit forward movement of the bar stock during advancement of the bar feed mechanism there is provided a stock stop 181 (FIG. 1) which is carried by the turrent on a selected one of its faces and which is positioned in the path of the bar stock when the bar stock is advanced by forward movement of the bar feed mechanism. The stop 181 operates to engage the advancing bar stock and to stop its movement so that a desired length of stock projects outwardly from the collet chuck. The stop 181 may be attached to the turret in any desired manner for indexing rotation with the turret. In some instances, it may be desired to employ a stock drop which is mounted by the turret for pivotal movement into and out of its operative bar stopping position. When such a pivotally mounted stop is employed it may be pivoted by means of a piston-cylinder arrangement 182 which is under the control of a valve 183. The arrangement 182;.

and the valve 183 are operated in a manner which is, similar to the operation of the previously described pistoncylinder arrangements and valves for the collet and barfeed mechanisms.

As previously stated, the machine is operated under the control of a number of electrical circuits. These circuits are diagrammatically represented in FIGS. 14 through 17 and include a plurality of switch contacts, relays, and relay contacts. Each relay includes a number of contacts and the contacts of a particular relay are represented by the same reference character as the relay with the letters a, b, 0, etc. following.

The switch contacts, relays and relay contacts are associated with electrical conductors which are diagrammatically illustrated as being arranged in vertically spaced rows which are numbered consecutively from 1 through 99 in FIGS. 14 through 17. The numbers of the rows which contain contacts of a particular relay are located to the right of the row which contains the relay. For convenience, when a particular circuit component is referred to the number of the row which contains that component will follow the reference character for the component in parentheses. The circuits may be energized from a conventional source or alternating voltage such as a transformer having a secondary winding S included in a wire 2% connected between power conductors L1 and L2. Relay contacts are illustrated in their normal open or closed position when the associated relay is de-energized.

In order to prepare the machine for receiving the first bar the machine control switch M on the panel P is set by an operator at its hand position. This results in closing of the switch contact 2111 in wire 2111' which causes energization of hand control relay H1 (39) in wire 21l2 which is connected to wire 2&1 and to conductor L2. This effects closure of contact Hla (31) and energization of hand control relay H2 (31) in wire 2% in parallel with Wire 2112. The main motor starter MMF (15) in wire 284 connected to conductor L2 is energized from conductors L1, L2 through contact MMRa (15) of the main motor reverse contactor MMR (16) in wire 2115 in parallel to wire 2194, contact 2116 of a jog switch, contact TRRIH of a tap reverse relay, contact 2117 of switch ILSS and wire 225 so that normally open contact MMFa (78) in wire 268 is closed.

A collet selector switch C on the panel P is set to its open position which results in closing of its contact 299 (94) in wire 2111 to effect energization of the collet solenoid 156 (94) through contact HSRa (594) of a hand 1E5 spindle-speed relay HSR (76), now closed contact HZa (9 4) and wires 225;" and 225. I

The bar feed selector switch B also on the panel P is set to its forwardfposition which closes its contact 211 (96) in wire 212 to energize the bar feed solenoid-174 feed mechanism and when the collet is fully. open and,

the bar feed mechanism fully forward, the high pressure button may be released? I The bar may now be loaded so. that the end ofthe bar extends through the collet sufficiently far to permit the cutoff tool to rnake a cut. The collet selector'switch C istnow set to its,close position which opens its contact. 209 to de-energize the, solenoid 156 and the high pressure. pushbutton HP is pressed to close its contact 213 which effects closing of the collet, When the collet is fully closed, the bar feed selector switch B is set to its back position. whichopen its contact 211 to de-energize solenoid 174 which causes retractionof the bar feed mechanism and when the bar feedrmechanism is fully back, the high pressure button is, released.

The spindle speed selector switch55 is actuated to close a selected one of its contacts SS1 (68), SS2 (66.),sand S83 (64) in parallel connected wires 217, 218 and 219. The spindle control selector-switch SC is now set to its run position which closes its contact 226, (68) in wire 221,which causes energization of relayl-ISR ('70 When this occurs the HSRb, c and d contacts (64, 66 and 68) in wires 217, 218 and 219 .are closed to effect energizationof the selected one of the solenoids-SVA, SVBjand SVC (65, 67' and 69) in wires 222, 223 apd224 connected inparallel to the wire 22 5 and conductor 62 through now closed contact H20 in wire 22 1 andthrough wire 225'.

Thecutroff slide62 is now movedforward ata rapid traverse speed by pushing, cut off rapid traversepush button CO to close itsrcontact 226 (83) in wire 227 which energizes relay COPR (83) in wire 227;' This push button is released when the cut off tool is near the bar. The cut oiffeed push'button COFis now depressed to close its contact 229 (7-) in wire 228 toenergize the cutoif feed clutch solenoid-230 (6) in wire 231 and the cut-ofislide 62 now feeds forward until cut ofl? of a small piece of thebar isaccomplished. The cut ofl. rapid traverse pushbutton is nowtdepressed until-the slide is fully retracted.

After the first barsis loaded and thestooling and ma-,.

chine setup is completed, and the bar has beensquared by cutting off a small piece of the bar as above described, the operator sets the machine control switch to the automatic setting which closes the contact 232 (32-)- to effect energization of'relay A1 (32) in wire 233 from conductors L1, L2 through wire 225, normally open but now closed contact 234, (27) in wire 235 of switch CDLS4, which is operated when the turret is in its present back position, wire 236, normally open but now closed contact GRa (31), contacts H2d and A2a (30) in wire 237 and contacts H1b.(32) and l-I2e (32) in wire 233. When relay A1 is energized its contact Ala (33) in wire 237 in parallel with wire 233 closes to energize relay A2.

The operator then presses the cycle start button CS which closes its contact 238 (35) in Wire 2339 and, operates to establish a circuit to the turret rapid-traverse forward relay RTFR (38) in wire 240 and a timing relay TR (35) in wire 241. This circuit may be traced from the conductor L1 through contact PMa (8) of the hydraulic pump motor starter PM (2) in wire 242, wire 225, normally open but now closed contact GRb (32) of the Geneva relay GR (12) in wire 243, contacts AZb (34), RTRa (34), CDLS10a (34), CDLS6a (34),

which starts the motor127 to drive the turret forward at a rapid traverse speed."

A holding circuit to relay RTFR, timer TR and starter RTF is established through the same circuit as above described from conductor L1 to contact Alb (35) from whichthe holding' circuit is traced through contacts EFRa (as orILIRb (37 it closed, RTFRa as), FLs4a (37), TER (36), 3FRa (36), 1a (36), and TRrz (36) to conductorL2.-

As the turret movesforward a speed dog 10;: on the control, drum 13 operates spindle speed limit switch SLS4 which closes its contact SLSda (76) in wire 246 to establish a circuit tospindle speed relay SR (76) in wire246. When relay SR isenergized its contacts SRa,

b and c (71, 73 and in parallel connected wires'247, 243-and 249. close to prepare for energization spindle speed selector relays SR1 (71), SR2 (73) and SR3 (75). As the turret continues to move forward speeddog operates a selected, one of a plurality of spindle speed limit switches SLSI, SL52 and'SLSS which close their contact-e256, 251and 252' (71, 73 and 75) and complete one of the previously prepared circuits to the spindle speed seleetorrelays SR1, SR2 and SR3. The energized one of these selector relays closes its contact SR1a, SR2a or SR3a (65, 66 and 67) to establish a circuit to one of the spindle clutchsolenoids SVA, SVBfand SVC (6 5, 6,7 and 69). This causes the spindle to rotate at the selected speed 'At the same timea feed dog lila on the drum Idoperates-feed limit switch ELSA Which closes its contact FLSdb (St?) in wire 254 to establish a circuit to feed rate relay FR (56),). When relay PR is energized its contacts FRa, b and c (4. 56 and 48) in parallel connected wires 255, 256 and 257'close to prepare for energization feedrate selector relays 11 R; (44'), 2BR (46) and3FR (:48). These feed rate relays are in shunt circuits which are connected to aseries circuit including contacts PMa and GRb, and contacts A2b,RTR a, CDLSltia, CDLSficz, CDLS9a, vCDLSfia andCDLSla all in wire 266 Asthe turret continues to move forward a feed-dog 10a operatesa selected one of aplurality of turret feed limit switlhes FLSTl, FLSZ and PLS3 which closes its contact 258, 2 59 or 266 (44., 46 or '48) to complete one ofthe previously prepared circuits to effect energization of one of theflfeed relays IFR etc. Theenergized one of the feedrelays-closes its contact 3ERb, ZFRaor lFRb (22, 23;or 24) in Wires 26 1, 262 and 263 to prepare a circuit to one of thefeed clutch solenoids FVA, FVB and PVC (Z2, 23 and 24), i

When a feed relayis energized-its contact- 1FRa (36) or SFRa (36) opens in the previously 'dscribed holding circuit for relays RTER, RTR and-TRE to interrupt the holding circuit so that the rapid traverse forward movement of the turret is stopped.' At thispoint the timer TR times out to close its contact TRb (24) in wire 26 t which effects energization of the selected feed clutch solenoid sothat the turret now' moves at the selected, feed speed and the tools carried thereby perform a machining operation on the bar.

At the end of the forward travel of the turret, the limit switch CDLS1 is operatedand opens its contactCDLSla (34) in wire 266 to interrupt the circuit to the selected feed relay 11 R, 215K or 3FR to stop therfeed movement of the turret. Operation of switch CDLS1 alsocloses a.

contact CDLSlb (55) in wire 26S-to complete a circuit to the turret rapid traverse reverse relay RTRR- (52) in wire 269 through closed-contacts PMa (8), GR Alb' (34), CDLSlb (55), lLS6'a (55), LCSa (5 

1. A MACHINE TOOL FOR OPERATING ON A LENGTH OF BAR STOCK COMPRISING MEANS FOR FEEDING THE BAR STOCK TO POSITION A PREDETERMINED PORTION TEHREOF IN MACHINING POSITION, MEANS FOR MACHINING THE PREDETERMINED PORTION OF THE BAR STOCK INCLUDING CROSS AND TURRET SLIDES AND AN INDEXIBLE TURRET ON SAID TURRET SLIDE, A CUTOFF SLIDE ADAPTED TO CARRY A CUTOFF TOOL AND MOVABLE TO CUT SAID BAR STOCK TRANSVERSE TO THE ELONGATION THEREOF, CYCLE CONTROL MEANS FOR CYCLICALLY OPERATING SAID MACHINE THROUGH A WORK CYCLE WHICH INCLUDES THE FEEDING OF A PREETERMINED PORTION OF BAR STOCK TO MACHINING POSITION, MACHINING SAID PORTION 